This invention relates to an indexable cutting insert for chip removing machining of right-angled corners in a work piece. The cutting insert which has a square basical shape has at least four main cutting edges, each transforming into a minor cutting edge at each cutting corner. Each minor cutting edge projects peripherally from the square basical shape so that the passive main cutting edge closest to the bottom work surface will not abut the same at machining.
Indexable cutting inserts inserted into cutting tools for milling of right-angled corners in work pieces usually have a rombic or triangular configuration. These inserts comprise only two or three cutting edges and said configurations are believed to be the only shapes which can be used when machining of right-angled corners with requisite side clearance. Using a conventional right-angled cutting insert having a radial or axial angle for milling or turning of an internal side surface is not possible due to its inner corner skidding on the machined surface. Thus, it has been common to use an insert having an acute angle between the main and the minor cutting edge for machining of an internal right-angled corner or right-angled inserts inserted in the tool body having a negative radial angle and a positive axial angle.
The present invention relates to an indexable cutting insert having at least four main cutting edges whereby the abovementioned drawbacks may be avoided.